In the marketing of solid compact medicaments, there is a clear consumer preference for a shiny, capsule-like, single or multiple color solid dosage form that is easy to swallow. Generally, gelatinous coatings have been used to achieve a shiny surface on a solid dosage form, also referred to herein as a caplet, pill, tablet, and the like. Caplets are solid, substantially cylindrical shaped medicaments; pills are solid, substantially round shaped medicaments; and, tablets are solid, substantially spherical shaped medicaments (see for reference Seitz et al., "Tablet Coating," Chapter 12, Page 346, The Theory and Practice of Industrial Pharmacy). One method of making caplets which has been used to meet the needs of the pharmaceutical consumer is described and illustrated in U.S. Pat. No. 4,965,089 to Sauter et al, and U.S. Pat. Nos. 4,990,358 and 4,921,108, both to Berta et al. In particular, Sauter '089 and Berta '358 each teaches a method and apparatus for holding and dipping one end portion of a caplet into a gelatin pool and then positioning the caplet so as to dip the uncoated end portion of the caplet into a second gelatin pool of a different color. However, a major drawback of the apparatus and methods taught in these patents is that a constant force spring is relied upon to hold the caplet during the dip coating process and also during caplet transfer to other processing steps, such as drying and packaging. As can be readily appreciated, such a constant spring force could impart a shear force which would be unacceptably large on some abrasion sensitive material included in solid compact medicaments. Acetyl salicylic acid, also known as aspirin, and gelatinous coatings which have not been completely cured, are two examples of abrasion sensitive materials which could be damaged by such shear force.
Furthermore, since existing caplet holders generally rely upon a constant force spring for holding the caplet, they require some sort of mechanical force to load the caplet into and discharge the caplet from the holder, thereby potentially compromising the integrity of the caplet material. For instance, Sauter '089 and Berta '108, each teaches a caplet loading device having a caplet feeder associated with a plunger assembly for mechanically loading and unloading caplets.
Accordingly, there persists a need for a reliable, relatively low maintenance apparatus having few moving parts for holding and releasing a solid compact medicament during processing which does not impart an unacceptably large shearing force on the solid compact medicament, subject the solid compact medicament to lubricant contamination, nor rely upon excessive forces to release the solid compact medicament from the apparatus.